Gravity-Based Angle Indicator Conflicts Many CRs, especially infant CRs, have a built-in device that indicates a range of correct angles. These devices vary in design, but typically all have a component (i.e., a dial, ring, bubble) that responds to gravity to indicate to the user when the CR is installed within an acceptable angle range. (At lease a couple of designs even specify different ranges for younger and older occupants.)
CPSTs, who are taught that a typical RF angle range is between about 30 and 45 degrees, sometimes question the accuracy of these devices, and some test the angle with an angle-reading tool (such as those available as apps on some cell phones) instead of using the CR’s built-in indicator. However, CR manufacturers strictly prohibit this; they prefer that users rely only on the angle directions described in the owner’s manual. It is important to remember:

Not all CRs are made to be used exactly in the 30 to 45 degree range.

Due to varying CR contours, it is often difficult to visually judge an appropriate angle simply by looking at it from the side.

Today’s CR models usually are not at the correct angle when placed on a horizontal surface, so angle assessments that use this technique are often flawed.

If a CPST has serious concerns about the accuracy of a CR’s angle indicator, the CPST should advise the caregiver to contact the manufacturer rather than ignore it or change the CR angle. Providing the manufacturer with a photo of the situation usually helps. Sometimes, switching to a different model CR must be considered.
Another variation in angle indicator designs is location—on the CR’s side versus by the feet, on the CR versus the base, etc. A few, such as the Britax infant CRs, are unusual in that they have two indicators, one located on either side of the CR shell. (See box below for more information specific to the Britax Chaperone.)

“Unpropped” CRs That Are Too Reclined To adapt to sloped vehicle seats, a recline foot that can be adjusted to suit the vehicle was added long ago to many CR models, and typically a rolled towel or pool noodle is allowed if this foot is inadequate or is not present. Some CRs also have been designed so that even an unpropped base will correct for some amount of vehicle seat slope. When this type of a design is paired up with a vehicle seat that is less sloped (more flat) than most, a problem sometimes occurs—the CR indicator shows the CR is too reclined when no method of propping has been used.
When this happens, there is typically no way to make installation corrections since there is no propping material to remove to make the CR more upright. Solutions are typically limited to trying another seating position in the vehicle, trying another CR model, or installing without the base. The exception is convertible CRs by Diono (formerly Sunshine Kids). For its Radian series (including the new R-series and older Radians sold under the Sunshine Kids brand), Diono has created a foam angle adjuster that can be placed under the part of their rear-facing CRs that is below the buttocks to prop the CR more upright. Instructions specify that this device should only be used when the child is over age 1 and can sit up well. It should be inserted only up to (NOT under) the CR’s RF angle foot (its “detachable base” attached under the foot end of the CR when rear facing). Besides propping up a CR that is over-reclined, this option allows older children to ride more upright within the allowable range and also helps the CR to fit within the depth of the rear seats.
The angle adjuster can be purchased for about $10 from some retailers or at us.diono.com (under Car Seat Accessories).

Forward-Facing Level-to-Ground Lines Think level-to-ground lines are only for RF CRs? Think again! At least one FF CR, the Safety 1st Rumi combination CR, has a level-to-ground line. So, it pays to always look carefully at labels and instructions.

Small Back Seats vs. Tall RF CRs Encouraging caregivers to keep children rear facing to age 2 or beyond means that bigger CRs for taller children will need space in the back seat. Can a CR for a taller RF child fit properly in the back seat of a vehicle with a short space fore and aft?
Issues of correct RF angle of recline and pressure against the seatback both come into play in these situations. Possible remedies depend on the specific circumstances, but here are a few:

Use the center position, if the area between the front seats provides more space for a better fit, or move the front seat forward, if possible.

Try another rear-facing CR that is not as tall as the existing CR but still fits the child.

For an older child, call the CR manufacturer to see if it allows a more upright position.

Check the CR and vehicle instructions (or LATCH Manual) for warnings about pressing the CR against the back of the front passenger seat.

Britax Chaperone: What to Do When Bubbles Disagree The Britax Chaperone infant CR, which has two bubble-style indicators (one on each side of the shell), has caused confusion because many users have reported installations in which one indicator says the CR is at the correct angle, while the other one is out of the correct-angle zone (usually indicating the CR is too reclined, even though the CR is not propped back). Britax has responded with an information sheet posted at www.britaxusa.com. (To find it, look under “Support,” then “Installation Videos & User Guides.” Enter Chaperone and any date into the search field. At the bottom of that page, click on the PDF for “Helpful Installation Tips.”)
On the sheet, Britax first advises users with this problem to ensure both that the vehicle is on a flat surface and the bubble is capable of moving freely in the indicator. If this is the case, then it is fine to rely on the one of two indicators that says that the CR is reclined properly. Britax also notes that the bottom of the grey box that houses the bubble vial should be parallel to the ground when the CR is properly installed.